To the Editor.—The excellent study of Gorse et al1 compared the clinical and laboratory characteristics of meningitis in patients of two age groups—15 through 49 and greater than 50. Several important differences, including etiologic agents involved, occurred in these two groups. Throughout the report the authors appropriately referred to the greater than 50 years of age group as "older" and "mature," but not as elderly. However, the title of the article, "Bacterial Meningitis in the Elderly" is probably somewhat misleading. While the definition of elderly is a difficult and elusive one, few geriatricians would be comfortable with "greater than 50 years of age" as representative of an elderly population. This criticism does not challenge the results of the study, but it is possible that a more standard definition of elderly (as more than 65 years of age) would better clarify true differences in the characteristics of meningitis with